Abstract 2662: Brain Natriuretic Peptide Levels Predict Stroke Outcomes in the Acute Rehabilitation Setting

Abstract

Introduction: Brain natriuretic peptide (BNP) is a known predictor of cardiovascular morbidity in patients with heart failure, and can predict cardiovascular complications in patients without known cardiovascular disease. Recent studies have focused on the relationship between elevated BNP levels and ischemic stroke. Increased BNP levels were correlated with increased for risk of stroke or transient ischemic attack. Plasma BNP levels are elevated in patients with acute ischemic stroke and predict death in acute ischemic stroke patients with atrial fibrillation. Hypothesis: Admission BNP (aBNP) levels predict outcomes in an acute rehabilitation setting. Methods: 763 patients with ischemic stroke admitted to an acute inpatient rehabilitation unit were assessed. Admission BNP levels, admission and discharge Fugl-Meyer Motor Impairment (FMMI) scores and Functional Independence Measure (FIM) score were obtained for each patient. Odds ratios were calculated for aBNP quintile groups and need for transfer to acute care or death versus other discharge disposition (ACDvsO). Spearman Rank Order correlations were calculated for aBNP levels and cardiovascular comorbidities and complications, admission and discharge FMMI and FIM scores. Logistic Regression was used to assess interactions with age and the above co-variables. Results: aBNP quintile cut scores showed the following odds ratios and confidence intervals for ACDvsO discharge disposition: aBNP > 17.5 (O.R.=1.6; CI = 0.83-3.12 ; p=N.S); > 49.5 (1.83; 1.09-3.07; p= 0.02); > 104.9 (2.03; CI = 1.27-3.25; p=.003); >231.3 (2.03; CI = 1.22- 3.38; p= 0.006). aBNP was still a significant predictor of ACDvsO (X2 =6.84;p=.009) with age, admission FMMI and FIM scores entered as co-variables. aBNP was significantly correlated with admission FIM (r=-0.21; p=0.000); discharge FIM (r=-.245; p=0.000) but not with admission FMMI (0.001; p=0.98) or with discharge FMMI (0.019; p=0.70) Conclusion: Rehabilitation Hospital aBNP values can predict a two-fold increase in odds of death or need for transfer to acute care. They are also correlated with admission and discharge FIM scores perhaps indicating less cardiovascular reserve and poor endurance due to underlying cardiovascular disease. Previous studies have correlated BNP levels with stroke severity, however our analysis failed to find a correlation between BNP and FMMI as a measure of motor impairment. Patients with high aBNPs need to be closely monitored for adverse events and rehabilitation intensity needs to be tailored to their needs.